Neither insightful enough to be biographically worthwhile nor camp enough to be enjoyably trashy, J Edgar occupies a dull wasted-opportunity middle ground. Director Clint Eastwood has complained that adult dramas no longer get much respect in Hollywood, but this is exactly the kind of self-important bore that studios can’t be blamed for avoiding.

Leonardo DiCaprio stars as J Edgar Hoover, a closeted and emotionally constipated mama’s boy who comes of age in the 1920s. He is so devious, self-righteous and sociopathic that he naturally rises to high office in Washington DC, where he is named the first director of what will become the Federal Bureau of Investigation. Through various forms of deceit, blackmail and questionable public relations efforts, Hoover raises the FBI’s profile and his own.

DiCaprio is never fully believable as the weaselly, insecure and nasty title character. He’s not helped by a screenplay (by Milk writer Dustin Lance Black) that flits back and forth in time so much that the film is more a series of anecdotes than a cohesive story. The conceit that Hoover is dictating recollections to a series of FBI agents for a potential book feels trite even taking into account that the subject is an unreliable narrator.

The makeup and prosthetics used to age DiCaprio and other characters aren’t sufficiently state-of-the-art for a major motion picture. The perpetually youthful DiCaprio can’t pass for a 77-year-old man no matter how many age spots freckle his latexed head. As Hoover’s assistant and longtime companion Clyde Tolson, Armie Hammer (who played both Winklevoss twins in The Social Network) is even more ill-served. In his character’s scenes as an elderly stroke victim, Hammer looks about as convincing as the rubber-headed half-dead grandpa in The Texas Chain Saw Massacre who had trouble holding onto a…hammer.

Hoover comes off more like a fussily nervous Norman Bates than a real human being. One of the movie’s most overbaked scenes features his bitchily domineering mother (Judi Dench) taking him to task for saying he doesn’t like dancing with women. Reminding him about a former schoolmate who was attacked for attracting the wrong kind of attention, Mrs H announces that “I’d rather have a dead son than a daffodil for a son.”

A scene in which Hoover and Tolson come to blows after Hoover unfeelingly remarks “it may be time for a Mrs Hoover” is likewise more laughable than tragic. Tolson’s screeching accusation that Hoover is “a scared, heartless, horrible little man” leads to a bloody-mouthed kiss. Ah, romance.

Exchanges such as those, and a later moment in which Hoover lives up to his tabloid legend by putting on his mother’s necklace and dress, feel more like feeble fiction than fact. It’s similarly doubtful that Hoover got the news about JFK’s assassination while listening to surveillance recordings of Martin Luther King Jr having sex — and even more unlikely that Hoover would leave that tape playing loudly enough for his caller to hear it.

Naomi Watts doesn’t have much to do as Helen Gandy, Hoover’s lifelong secretary. Josh Lucas cameos as Charles Lindbergh, whose baby’s kidnapping was one of the FBI’s biggest early cases.

Obvious parallels are drawn between the mid-century FBI’s overzealous tactics for keeping the communist boogeyman at bay and America’s current police-state anti-terrorism efforts. Hoover may be gone, in other words, but things still suck.

[Rating: 2 stars]

J Edgaropens in limited release on Wednesday November 9, 2011, and a wide release two days later on Friday November 11, 2011